Thread: Why the function getchar () is skipped, and does not run in the above program in C

  1. #1
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    Why the function getchar () is skipped, and does not run in the above program in C

    Code:
    /*I tried to make a simple program, that calculate: 
     *1) how much money will cost us a product if we have percentage decrease for it; 
     *2) how much money we can save after buying a reduced/decreased product versus its real price; */
    
    
    /*I want to implement some of the two cases in switch statement, but the program does not allow me to do that, because the getchar () function is skipped*/
    
    
    #include <stdio.h>
    
    
    int main (void)
    {
        float real_price, percentage;
        char ch;
    
    
        printf ("Enter the real price of the product: ");
        scanf ("%f", &real_price);
        printf ("\nEnter the percentage decrease: ");
        scanf ("%f", &percentage);
    
    
        printf ("\nPress 1 if you want to calculate the PRICE OF THE PRODUCT AFTER THE REDUCING\nPress 2 if you want to calculate THE REDUCED PRICE OF THE PRODUCT: ");
        ch = getchar ();  //this statement is not implemented
    
    
        switch (ch) {
            case '1':
                printf ("The price of the product after the reducing is: %f ", real_price - (percentage / 100) * real_price);
    
    
            case '2':
                printf ("The reduced price of the product is: %f", (percentage/100)*real_price);
                break;
    
    
            default:
                printf ("getchar () is not implemented\n");  //respectively this statement is implemented
        }
    
    
        return 0;
    }

  2. #2
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    scanf leaves '\n' in the input buffer, that's what getchar reads so it doesn't stop for input.
    To fix put another getchar after the last scanf.

  3. #3
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    I understand you and i am thankful for your explanation and advice, but I do not understand a few things associated about what you wrote about getchar()
    First thing: why scanf() still keeps the '\n' after releasing the '\n' on printf() ?
    Second thing: why scanf() does not release the '\n' on such functions as getche(), getch() ?
    Last edited by timcook; 08-07-2018 at 04:37 AM.

  4. #4
    Programming Wraith GReaper's Avatar
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    1) Because its input is buffered, and it doesn't discard characters willy-nilly.
    2) Because getche() and getch() aren't buffered
    Devoted my life to programming...

  5. #5
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    I understand the conception, and I will follow the URLs that you shared with me. Thank you very much!!!

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